#define _U 0x01    /* upper */
#define _L 0x02    /* lower */
#define _D 0x04    /* digit */
#define _C 0x08    /* cntrl */
#define _P 0x10    /* punct */
#define _S 0x20    /* white space */
#define _X 0x40    /* hex digit */
#define _SP 0x80   /* hard space */

extern unsigned char _ctype[];

#define __ismask(x) (_ctype[(int)(unsigned char)(x)])

#define isalnum(c) ((__ismask(c)&(_U|_L|_D)) != 0)
#define isalpha(c) ((__ismask(c)&(_U|_L)) != 0)
#define iscntrl(c) ((__ismask(c)&(_C)) != 0)
#define isdigit(c) ((__ismask(c)&(_D)) != 0)
#define isgraph(c) ((__ismask(c)&(_P|_U|_L|_D)) != 0)
#define islower(c) ((__ismask(c)&(_L)) != 0)
#define isprint(c) ((__ismask(c)&(_P|_U|_L|_D|_SP)) != 0)
#define ispunct(c) ((__ismask(c)&(_P)) != 0)
#define isspace(c) ((__ismask(c)&(_S)) != 0)
#define isupper(c) ((__ismask(c)&(_U)) != 0)
#define isxdigit(c) ((__ismask(c)&(_X|_D)) != 0)

#define isascii(c) (((unsigned char)(c)) <= 0x7f)
#define toascii(c) (((unsigned char)(c))&0x7f)

static inline unsigned char __tolower(unsigned char c)
{
	if (isupper(c))
		c -= 'A'-'a';
	return c;
}

static inline unsigned char __toupper(unsigned char c)
{
	if(islower(c))
		c -= 'a'-'A';
	return c;
}

#define tolower(c) __tolower(c)
#define toupper(c) __toupper(c)
